refractor(google-maps): use Observable.fromEvent instead of addEventListener (#1032)
refractor(google-maps): use Observable.fromEvent instead of addEventListener (#1032)


xueron/ionic-native,klirix/ionic-native,xueron/ionic-native,xueron/ionic-native,driftyco/ionic-native,klirix/ionic-native,driftyco/ionic-native,driftyco/ionic-native,klirix/ionic-native,xueron/ionic-native